🚀 go-pugleaf

<BigAl.NZ@gmail.com> wrote in message 
news:8fdab6cc-b21a-4ed7-9bac-2ed3b666c46c@x16g2000prn.googlegroups.com...
> Hi Guys,
>
> I need to get a VGA signal from the Nav Station in my boat to the
> monitor in the bridge. I could just run a VGA cable (about 4m worth)
> but I need to pass the cable through some small holes for the looming
> (sp?) and the DB15 connectors wont fit unless I make the hole bigger.
>
> I am thinking about running the VGA singal over CAT5e, which a Google
> search seems to suggest is possible. I was wondering if anyone had any
> better ideas, keeping costs fairly low.
>
> Has anyone here had any success cutting the end off a VGA cable and
> wiring on a new DB15 for example?
>
> Thanks in advance,
>
> -Al



Al

Well I was going to say different cable for different uses, but then I found 
this site:
http://www.geocities.com/dougburbidge/vgaovercat5.html
The author says they've achieved 15 metres.
For the cost of the cable and solder time, worth trying.

If that doesn't work you can get gadgets that convert from VGA to RJ45 and 
back again:
http://www.svideo.com/vgacat5.html

Best
Paul. 

On Sun, 5 Oct 2008 21:05:00 -0700 (PDT), BigAl.NZ@gmail.com wrote:

>Hi Guys,
>
>I need to get a VGA signal from the Nav Station in my boat to the
>monitor in the bridge. I could just run a VGA cable (about 4m worth)
>but I need to pass the cable through some small holes for the looming
>(sp?) and the DB15 connectors wont fit unless I make the hole bigger.
>
>I am thinking about running the VGA singal over CAT5e, which a Google
>search seems to suggest is possible. I was wondering if anyone had any
>better ideas, keeping costs fairly low.
>


http://www.google.com/search?hl=en&q=ethernet+vga+extender

generates 257,000  hits.

http://www.google.com/search?hl=en&q=kvm+cat5+extender

generates 140, 000 hits.

Here's a few that look promising:

http://sewelldirect.com/KVMcat5extender.asp

http://www.cablestogo.com/product.asp?cat_id=503&sku=39970






>Has anyone here had any success cutting the end off a VGA cable and
>wiring on a new DB15 for example?
>

You would need the skills of a micro-surgeon and a very fine solder
tip.

On Oct 6, 5:55 pm, Wayne.B <waynebatrecdotbo...@hotmail.com> wrote:
> On Sun, 5 Oct 2008 21:05:00 -0700 (PDT), BigAl...@gmail.com wrote:
> >Hi Guys,
>
> >I need to get a VGA signal from the Nav Station in my boat to the
> >monitor in the bridge. I could just run a VGA cable (about 4m worth)
> >but I need to pass the cable through some small holes for the looming
> >(sp?) and the DB15 connectors wont fit unless I make the hole bigger.
>
> >I am thinking about running the VGA singal over CAT5e, which a Google
> >search seems to suggest is possible. I was wondering if anyone had any
> >better ideas, keeping costs fairly low.
>
> http://www.google.com/search?hl=en&q=ethernet+vga+extender
>
> generates 257,000  hits.
>
> http://www.google.com/search?hl=en&q=kvm+cat5+extender
>
> generates 140, 000 hits.
>
> Here's a few that look promising:
>
> http://sewelldirect.com/KVMcat5extender.asp
>
> http://www.cablestogo.com/product.asp?cat_id=503&sku=39970
>
> >Has anyone here had any success cutting the end off a VGA cable and
> >wiring on a new DB15 for example?
>
> You would need the skills of a micro-surgeon and a very fine solder
> tip.

I am liking the ethernet idea. I found these mounts I could use which
have sealed end caps for when not in use:

http://au.farnell.com/1254803/connectors/product.us0?sku=amphenol-pcd-rjfrb71

This way it has a fighting chance of surviving in the marine
enviroment!

-Al

BigAl.NZ@gmail.com writes:

> Hi Guys,
> 
> I need to get a VGA signal from the Nav Station in my boat to the
> monitor in the bridge. I could just run a VGA cable (about 4m worth)
> but I need to pass the cable through some small holes for the looming
> (sp?) and the DB15 connectors wont fit unless I make the hole bigger.

How about cutting the connector from one cable end, pulling 
the cable and then soldering a new one to the end. 
Or building entirely new VGA cable the length you want 
by soldering the connectors yourself to both ends. 
The soldering the cable consisting of several mini 
coax condictors and many other conductor DB15 VGA connector 
is not the easiest job, but doable if you are good 
at building cables. I have done that kind of soldering 
myself when I have needed some custon VGA cables for 
some applications.    

> I am thinking about running the VGA singal over CAT5e, which a Google
> search seems to suggest is possible. 

Runnign VGA over CAT5e is possible. 
There are commercial active adapters that do the conversion  
"right" and work even for some longer distances. Those 
cost money but work quite well. 
Then in Internet there are some simple plans to run 
VGA over CAT5e cables. When you use a shielded CAT5e cable 
and not too long distances, those hacks can work quite well 
but might not give perfect "crystal clear" picture like 
a real VGA cable or commercial converter would give. 
Running VGA signal on unshielded CAT5e cable with simple 
DIY passive adapters is not a vry good idea: the image 
quality will get worse and your cable will radiate 
out considerable RF interference which could interfere 
for example with boat radios. 

> I was wondering if anyone had any
> better ideas, keeping costs fairly low.

I just gave you several ideas.
 
> Has anyone here had any success cutting the end off a VGA cable and
> wiring on a new DB15 for example?

Yes. I have done this several times.  

-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/

<BigAl.NZ@gmail.com> wrote in message 
news:8fdab6cc-b21a-4ed7-9bac-2ed3b666c46c@x16g2000prn.googlegroups.com...
> Hi Guys,
>
> I need to get a VGA signal from the Nav Station in my boat to the
> monitor in the bridge. I could just run a VGA cable (about 4m worth)
> but I need to pass the cable through some small holes for the looming
> (sp?) and the DB15 connectors wont fit unless I make the hole bigger.
>
> I am thinking about running the VGA singal over CAT5e, which a Google
> search seems to suggest is possible. I was wondering if anyone had any
> better ideas, keeping costs fairly low.

You have lots of replies to this already, but just curious as to whether 
you've considered instead putting a small laptop in your "bridge" and using 
remote desktop or vnc to control your "Nav Station" (assuming its a standard 
pc). You could even go wireless and avoid the need for cable runs all 
together.
-- 
Brian Cryer
www.cryer.co.uk/brian

BigAl.NZ@gmail.com wrote:

> I need to get a VGA signal from the Nav Station in my boat to the
> monitor in the bridge. I could just run a VGA cable (about 4m worth)
> but I need to pass the cable through some small holes for the looming
> (sp?) and the DB15 connectors wont fit unless I make the hole bigger.

> I am thinking about running the VGA singal over CAT5e, which a Google
> search seems to suggest is possible. I was wondering if anyone had any
> better ideas, keeping costs fairly low.

The impedance is different enough that you will get visible reflection
at anywhere close to VGA frequencies.  I believe VGA, like most analog
video signals, is 75 ohm coax (unbalanced).  Matching that to 100 ohm
balanced line is not easy with passive parts.   Using active circuitry
you can generate the balanced signal needed, and convert it back
at the other end.  That takes a number of very fast amplifiers
(I think three video, plus two sync, but I am not so sure about sync
signals for VGA.)

I believe the boxes are commercially available, because it is sometimes
the best way to send video long distance.  (The cheaper cable makes
up for the added cost of conversion.)

If you find the connectors with separate pins that you solder and
then install it isn't too hard.  You still want the appropriate
multiple coax cable, though.

> Has anyone here had any success cutting the end off a VGA cable and
> wiring on a new DB15 for example?

Finding ready made cables has been easy enough, and finding the
required cable in bulk hard enough, that I haven't tried.

-- glen

<BigAl.NZ@gmail.com> wrote in message
news:8fdab6cc-b21a-4ed7-9bac-2ed3b666c46c@x16g2000prn.googlegroups.com...
> Hi Guys,
>
> I need to get a VGA signal from the Nav Station in my boat to the
> monitor in the bridge. I could just run a VGA cable (about 4m worth)
> but I need to pass the cable through some small holes for the looming
> (sp?) and the DB15 connectors wont fit unless I make the hole bigger.
>
> I am thinking about running the VGA singal over CAT5e, which a Google
> search seems to suggest is possible. I was wondering if anyone had any
> better ideas, keeping costs fairly low.
>
> Has anyone here had any success cutting the end off a VGA cable and
> wiring on a new DB15 for example?
>
> Thanks in advance,
>
> -Al


VGA cable is shielded
and CAT5 is not, so you would get some horrible ghosting.

BTW, there may still be some ghosting even with VGA cable

On Sun, 5 Oct 2008 21:05:00 -0700 (PDT), BigAl.NZ@gmail.com wrote:

>Hi Guys,
>
>I need to get a VGA signal from the Nav Station in my boat to the
>monitor in the bridge. I could just run a VGA cable (about 4m worth)
>but I need to pass the cable through some small holes for the looming
>(sp?) and the DB15 connectors wont fit unless I make the hole bigger.
>
>I am thinking about running the VGA singal over CAT5e, which a Google
>search seems to suggest is possible. I was wondering if anyone had any
>better ideas, keeping costs fairly low.
>
>Has anyone here had any success cutting the end off a VGA cable and
>wiring on a new DB15 for example?
>



If you are handy with a soldering iron there is no problem. You may
have to buy a new plug/socket though as the one you cut off may be
potted. 

On Mon, 6 Oct 2008 17:23:03 +1300, "PeeCee" <abuse@local.host> wrote:

><BigAl.NZ@gmail.com> wrote in message 
>news:8fdab6cc-b21a-4ed7-9bac-2ed3b666c46c@x16g2000prn.googlegroups.com...
>> Hi Guys,
>>
>> I need to get a VGA signal from the Nav Station in my boat to the
>> monitor in the bridge. I could just run a VGA cable (about 4m worth)
>> but I need to pass the cable through some small holes for the looming
>> (sp?) and the DB15 connectors wont fit unless I make the hole bigger.
>>
>> I am thinking about running the VGA singal over CAT5e, which a Google
>> search seems to suggest is possible. I was wondering if anyone had any
>> better ideas, keeping costs fairly low.
>>
>> Has anyone here had any success cutting the end off a VGA cable and
>> wiring on a new DB15 for example?
>>
>> Thanks in advance,
>>
>> -Al
>
>
>
>Al
>
>Well I was going to say different cable for different uses, but then I found 
>this site:
>http://www.geocities.com/dougburbidge/vgaovercat5.html
>The author says they've achieved 15 metres.
>For the cost of the cable and solder time, worth trying.

I used to make up  VGA cables for control room applications. 15M using
individual screened conductors was about the recommended limit 

>
>If that doesn't work you can get gadgets that convert from VGA to RJ45 and 
>back again:
>http://www.svideo.com/vgacat5.html
>
>Best
>Paul. 

"philo" <philo@privacy.net> wrote in message 
news:eWH7PX6JJHA.468@TK2MSFTNGP06.phx.gbl...
>
> <BigAl.NZ@gmail.com> wrote in message
> news:8fdab6cc-b21a-4ed7-9bac-2ed3b666c46c@x16g2000prn.googlegroups.com...
>> Hi Guys,
>>
>> I need to get a VGA signal from the Nav Station in my boat to the
>> monitor in the bridge. I could just run a VGA cable (about 4m worth)
>> but I need to pass the cable through some small holes for the looming
>> (sp?) and the DB15 connectors wont fit unless I make the hole bigger.
>>
>> I am thinking about running the VGA singal over CAT5e, which a Google
>> search seems to suggest is possible. I was wondering if anyone had any
>> better ideas, keeping costs fairly low.
>>
>> Has anyone here had any success cutting the end off a VGA cable and
>> wiring on a new DB15 for example?
>>
>> Thanks in advance,
>>
>> -Al
>
>
> VGA cable is shielded
> and CAT5 is not, so you would get some horrible ghosting.
>
> BTW, there may still be some ghosting even with VGA cable
>

STP CAT5e or CAT 6 would do the trick, and at these lengths the cost 
difference isn't an issue.

-John O 

It might be worthwhile to think-out a bit beyond the size of the hole
though which you want to pass this signal.  Stuff like "what will
hold-up best when I'm at the bridge, in a storm, near a rocky shore
and I really need to know where I am?"  I say that only half in jest.

rick jones
-- 
oxymoron n, commuter in a gas-guzzling luxury SUV with an American flag
these opinions are mine, all mine; HP might not want them anyway... :)
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...

In article <lLWdnWYjiMT58HfVnZ2dnUVZ_tTinZ2d@comcast.com>,
 glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:

> JohnO wrote:
> 
> > "philo" <philo@privacy.net> wrote in message 
> (snip)
> 
> >>VGA cable is shielded
> >>and CAT5 is not, so you would get some horrible ghosting.
> 
> >>BTW, there may still be some ghosting even with VGA cable
> 
> > STP CAT5e or CAT 6 would do the trick, and at these
> > lengths the cost difference isn't an issue.
> 
> There might be a minimum amount that they will sell, but the
> real problem isn't shielding but impedance and
> balanced/unbalanced line.
> 
> If you transition from a balanced line (UTP) to an unbalanced
> line (coax), unless exactly impedance matched, it won't
> work right.   UTP cable depends on the voltage and currents
> on the two wires being exactly opposite to cancel out and
> not radiate the signal.  Coax depends on the voltage on the
> shield being zero.  To couple between them you either need
> a transformer (if there is no DC component), or active
> circuitry such as differential amplifiers.  VGA has a
> DC component so you can't use transformers.
> 
> -- glen

You can use a transformer, but wired as a *balun* (coils in series with 
the lines instead of across them); this provides the required impedance 
transformation while still passing DC.


--
Rich Seifert              Networks and Communications Consulting
                          21885 Bear Creek Way
(408) 395-5700            Los Gatos, CA 95033
(408) 228-0803 FAX

Send replies to: usenet at richseifert dot com

JohnO wrote:

> "philo" <philo@privacy.net> wrote in message 
(snip)

>>VGA cable is shielded
>>and CAT5 is not, so you would get some horrible ghosting.

>>BTW, there may still be some ghosting even with VGA cable

> STP CAT5e or CAT 6 would do the trick, and at these
> lengths the cost difference isn't an issue.

There might be a minimum amount that they will sell, but the
real problem isn't shielding but impedance and
balanced/unbalanced line.

If you transition from a balanced line (UTP) to an unbalanced
line (coax), unless exactly impedance matched, it won't
work right.   UTP cable depends on the voltage and currents
on the two wires being exactly opposite to cancel out and
not radiate the signal.  Coax depends on the voltage on the
shield being zero.  To couple between them you either need
a transformer (if there is no DC component), or active
circuitry such as differential amplifiers.  VGA has a
DC component so you can't use transformers.

-- glen

Rich Seifert wrote:
(snip)

> You can use a transformer, but wired as a *balun* (coils in series with 
> the lines instead of across them); this provides the required impedance 
> transformation while still passing DC.

So that is how they do it.

TV baluns, from 300 ohm balanced to 75 ohm coax, don't do that.

http://en.wikipedia.org/wiki/Balun

Does that restrict which impedance transformation you can make?

-- glen

On 6 Oct, 18:30, Rick Jones <rick.jon...@hp.com> wrote:
> It might be worthwhile to think-out a bit beyond the size of the hole
> though which you want to pass this signal.  Stuff like "what will
> hold-up best when I'm at the bridge, in a storm, near a rocky shore
> and I really need to know where I am?"  I say that only half in jest.
>

I have worked with commercial solutions using this technology.
Was about 5 or 6 years ago.

I forget the name of the product.

One serious problem was that by *design* (as I understand it)
the various different pairs in the cat5 cable have different
twist rates. This results in different cable lengths and
produces different delays for each of the
RGB and Sync. The solution overcame this by having
user adjustable delays controlled by DIP switches
at the remote end.

(or is sync on one of the RGB?) doesn't matter - is still broken.

NIGHTMARE - in the event of any moves or changes.

Not sure of your proposed length would run into this or not.
I suspect it would since the frequency required to drive
a display is rather high.

In the case I observed the differential delay issue
was *very* significant over two floors of
a narrow buillding.

There of course may be commercial solutions available now that
avoid the problems entirely. Perhaps by combining the
signals into one pair.

Composite Video?

On Mon, 6 Oct 2008 16:27:41 -0700 (PDT), Bod43@hotmail.co.uk wrote:

>There of course may be commercial solutions available now that
>avoid the problems entirely. Perhaps by combining the
>signals into one pair.

The most common solution now is to use an ethernet KVM (keyboard,
video and mouse) switch.  All signals get packetized.

>
> Not sure of your proposed length would run into this or not.
> I suspect it would since the frequency required to drive
> a display is rather high.

Length in this case 4m absolute MAX!

-Al

"philo" <philo@privacy.net> writes:

> <BigAl.NZ@gmail.com> wrote in message
> news:8fdab6cc-b21a-4ed7-9bac-2ed3b666c46c@x16g2000prn.googlegroups.com...
> > Hi Guys,
> >
> > I need to get a VGA signal from the Nav Station in my boat to the
> > monitor in the bridge. I could just run a VGA cable (about 4m worth)
> > but I need to pass the cable through some small holes for the looming
> > (sp?) and the DB15 connectors wont fit unless I make the hole bigger.
> >
> > I am thinking about running the VGA singal over CAT5e, which a Google
> > search seems to suggest is possible. I was wondering if anyone had any
> > better ideas, keeping costs fairly low.
> >
> > Has anyone here had any success cutting the end off a VGA cable and
> > wiring on a new DB15 for example?
> >
> > Thanks in advance,
> >
> > -Al
> 
> 
> VGA cable is shielded
> and CAT5 is not, so you would get some horrible ghosting.

Thethe wrong cable impedance and lack of shileding between 
RGB signals will not cause ghosting. Most ghosting will 
be caused by the impedance mismatches. 

The lack of shield in cable will cause that that cable  
will pick up more easily external interference 
and will radiate out more RF interference and properly 
shielded VGA cable.


> BTW, there may still be some ghosting even with VGA cable

True. The VGA cables vary in quality. The good ones are good 
but there are also bad ones. One thing to keep in mind 
in VGA connections is that it is a good idea to keep the 
number of VGA connectors along the link minimum (ideally 
only at source and destination), because the VGA connector 
impedance is not exactly 75 ohms as the system is designed 
for, and having many such wrong impedance connectors on 
the way will cause impedanc mismatches that cause 
reflections. For VGA cables is best to use a correct 
length cable in the beginning, and avoid using
orignal cable + extension cable combinations.    
  

-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/

In article <xcCdnUH-t6705XfVnZ2dnUVZ_qTinZ2d@comcast.com>,
 glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:

> Rich Seifert wrote:
> (snip)
> 
> > You can use a transformer, but wired as a *balun* (coils in series with 
> > the lines instead of across them); this provides the required impedance 
> > transformation while still passing DC.
> 
> So that is how they do it.
> 
> TV baluns, from 300 ohm balanced to 75 ohm coax, don't do that.
> 
> http://en.wikipedia.org/wiki/Balun
> 
> Does that restrict which impedance transformation you can make?
> 

The impedance transformation is determined by the winding ratio, 
regardless of whether the coils are in series or parallel with the 
lines. 

Putting the balun in series provides better low-frequency response (down 
to DC), but of course this configuration does not provide any electrical 
isolation. It functions very much like a common-mode choke, with an 
impedance change.


--
Rich Seifert              Networks and Communications Consulting
                          21885 Bear Creek Way
(408) 395-5700            Los Gatos, CA 95033
(408) 228-0803 FAX

Send replies to: usenet at richseifert dot com

"Alfred" <invalid@invalid.co.uk> wrote in message 
news:mv0ke4d8sag8dndkd0c0i3rq52l99ldjp5@4ax.com...
> On Mon, 6 Oct 2008 17:23:03 +1300, "PeeCee" <abuse@local.host> wrote:
snip
>
> I used to make up  VGA cables for control room applications. 15M using
> individual screened conductors was about the recommended limit



mmm wouldn't surprise me.
I've seen VGA extension cables as short as 2M exhibit ghosting.

P. 

"PeeCee" <abuse@local.host> writes:

> "Alfred" <invalid@invalid.co.uk> wrote in message
> news:mv0ke4d8sag8dndkd0c0i3rq52l99ldjp5@4ax.com...
> > On Mon, 6 Oct 2008 17:23:03 +1300, "PeeCee" <abuse@local.host> wrote:
> snip
> >
> > I used to make up  VGA cables for control room applications. 15M using
> > individual screened conductors was about the recommended limit
> 
> 
> 
> mmm wouldn't surprise me.
> I've seen VGA extension cables as short as 2M exhibit ghosting.

There are well built VGA extension cables (use 75 ohm mini coax cables 
at least for RGB signals). Those work generally well. 
Also there are those crappy cables built just from general purpose 
computer cable with lots of wires inside one outer shield. Those 
cheap cables have typically wrong impedance and considerable 
crosstalk between signals -> ghosting problems

Then the used resolution + refresh combination has effect. 
Almost any crapphy cable works for 640x480 60 Hz resolution 
but for 1280x12o4 and higher resolutions the quality of the cable 
starts really slow up.

-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/